whether the engoal is in ensuring cooperation with police, making sure kids get vaccinated or keeping kids you know are in the country illegally, make sure they stay in school, local authorities found it easier to turn their cities in so-called sanctuary cities. >> reporter: this food cart bustles at lunchtime. >> translator: we are very proud that immigrants are productive. that we are not a problem to the country. we are a solution. >> reporter: they are both undocumented but feel confident enough to call the police if they are in trouble. that's because philadelphia is one of 300 so-called sanctuary cities in the u.s. us. jurisdictions with local police have stopped enforcing federal immigration laws. >> if you have someone who is a criminal or you expect to be a criminal, or is on the run or they are wanted, go to a federal judge, get a warrant, and we'll be happy to told them for you. but we're not holding people at a whim. >> reporter: he argues it's impossible to run a city if migrants don't feel safe enough to make a living or feel too frightened to report a crime. >> if you c